Pinky Promise
by Vii Zee
Summary: AU where Cosima, Sarah and Alison grew up as triplets.


**Age 9**

"Cosima!"

Cosima stopped in her shoving of a jar with a spider in it in her sister's face and looked up at her mother, grinning broadly. "What, mommy?"

"What have we said about the insects?"

Cosima looked down at the spider in the jar and pouted. "But I was only showing Kyle to Sarah!"

"Kyle's icky!" Sarah yelled, pushing the jar away from her and, in the process, shoving Cosima backwards too, causing her to fall onto her backside in a confused heap, clutching the jar with her precious pet spider, Kyle, tightly to her.

"Cosima," her mother said gently, kneeling down to look at her eye to eye, "listen to me, pet; just because you like spiders doesn't mean your sisters do."

"What about butterflies? And ladybirds?"

"Those too. Any insects. OK, pet?"

Cosima nodded. "OK."

"Now, apologize to Sarah and to Alison for forcing them to look at Kyle."

Cosima hung her head, trying her best to avoid Alison's tearful face behind their mother and Sarah's scowl in front of her. "Sorry."

"Good girl."

-0-

**Age 10**

"Mommy, mommy, please!"

"Alison, you know we can't afford ballet lesson! I'm sorry, pumpkin."

Sarah and Cosima sat on the stairs, listening intently to the exchange their mother was having with their sister, and looked over at each other worriedly. They both knew how much dancing meant to Alison, and how happy she would be if she could start lessons. She was made for it, and they wanted her to be happy, annoying as she was sometimes.

"What do we do?"

"Well, I could tell Mom to stop going to karate lessons?" Sarah muttered to Cosima, and Cosima nodded.

"I could tell her I don't want to go to piano anymore."

"We could save up enough money…"

"And they can afford to send Alison to ballet!"

"OK!" Sarah grinned, and got up, rushing down the stairs two at a time to find their mother in the kitchen, hugging a sniffling Alison.

"Mom, Mom, we can fix it!"

That summer, Alison started ballet lessons at the local dance centre, and Sarah and Cosima had to content themselves with going to recitals and being bored out of their mind.

But at least Alison was happy.

-0-

**Age 13**

"Cos?" Sarah crept into the attic, bumping her head clumsily on the trap door as she searched around for her sister. "Cos, you up here?"

"Yes," she heard a small whisper, and turned to see Cosima pointing a flashlight at a cardboard box.

"What you got there?"

"Shush! Quiet or you'll disturb them!"

Sarah raised an eyebrow as she crawled over to Cosima, peering into the box. "What the fuck are those white things?"

"Where are you learning these swear words from, Sarah?"

"The big kids at school?"

"Whatever. And they're silk worms."

"Why do you have silk worms?"

Cosima shrugged. "Science project."

"That's a lie."

"Don't tell Mom."

"I won't," Sarah promised, extending her pinky. Cosima took it, and they linked for three brief seconds before unlinking and pressing the pinky to their lips, kissing it quickly before going back to staring at the box's contents.

"Hey, you know what?"

"What?"

"You should totally show these to Alison."

**Age 16**

"Sarah, seriously?"

"Wha'?" Sarah grinned as she sat on the hood of Alison's car – well, really, it was their car, they just shared it, and it was Alison's turn to drive that week – and flicked her hair behind her shoulder, flashing her winning smile at the boys passing by them. "Nothing wrong with a little male attention, yeah? You should try it."

"No, thanks, Sarah," Cosima muttered as she sat next to her, huffing away silently. "I'd much rather focus on important things."

"Yeah, like what?"

"Like how I'm probably failing my biology test in eight period."

"Oh come on, we all know you're going to pass that easy."

Cosima shrugged, and turned to Alison, who was reading from the novel she had stowed away in her book bag and slapped her gently on the shoulder.

"Tell your sister that the clothes she's wearing under that jacket are too revealing."

"Right, coz she's not obeying school rules, now she's _my_ sister."

"She's only my sister when she's a smart ass, we both know that."

Sarah rolled her eyes at their banter and continued to wink at any of the boys passing by. Really, it was all a game to her. She wasn't interested, she just liked making heads turn.

-0-

**Age 17, Part One**

"Sarah?"

"Yeah, Ali?"

Alison stepped gingerly into her sister's room and wrung her hands as she stepped closer to Sarah, who was lying in bed with a book held above her face as she mouthed French to herself.

"I need to talk to you…"

"About…?"

"About Cosima."

Sarah putt the book down and stared at Alison, frowning slightly as she spoke. "What about Cosima?"

"Well…" Alison mumbled, looking around just to make sure that their twin sister wasn't in the room too, and sat on the edge of Sarah's bed, bending down conspiratorially.

"I've been hearing…rumors…"

"Yeah, so have I. And?"

"Sarah, doesn't it worry you?"

"What? That our sister might be gay?"

Alison blushed at the words, and Sarah found herself giggling as she sat up and put a hand on Alison's shoulder, shaking her slightly. "Ali, so what?"

"I just don't want things to be bad for her. For us."

"They won't be. Coz I'll kick the ass of anyone who fucks with her."

"Sarah…"

"Alison, listen to me. So what if she is?"

"I just don't want her to be hurt."

Sarah sighed, extending her pinky at Alison, who took it gingerly and completed the ritual, just as they always did, with a kiss on the pad of her pinky.

"I promise you, things will be fine."

-0-

**Age 17, Part Two**

Sarah and Alison had been planning this moment for days, ever since Sarah had promised she would keep Cosima safe. And even though she meant it, that didn't mean she would keep her safe from any teasing from her family.

They lay in wait in the dark living room, knowing that Cosima had just pulled up into the drive way in someone else's car. They stealthily crept to the window, pushing the curtain aside enough to be able to look out without giving themselves away. Cosima was climbing up the porch steps, a red headed girl right behind her. It was a clear night, and even with the porch light off, it was enough for them to see the large grin on Cosima's face and the way that the other girl – what was her _name_? Samantha…something. She was in Cosima's Advanced Calculus class – pulled her to her and kissed her. Alison and Sarah turned to each other and slapped palms before rushing to the front door and pulling it open, giving out half-yells, enough to give the two girls on the porch a fright.

"Jesus Christ!" Cosima yelled, swiping at them with her hands as she did, and the two of them retreated back into the house, laughing as they watched their sister step into the door frame and glare at them.

"A little privacy, please?"

"Use protection, Cos!" Sarah yelled at her, Alison too bent up with laughter to say anything. Cosima rolled her eyes, flipping her off before saying, "Maybe I'll borrow some from your stash!" She slammed the door, and Sarah and Alison heard her say something along the lines of "Where were we?" even behind the closed door. Grinning at each other, they sat on the steps and waited for her to come back inside and bore them to death with excruciating details of how her date had gone.

-0-

**Age 17, Part Three**

"So you and Samantha, huh?"

Cosima nodded, a silly grin plastered all over her face, and Sarah patted her knee as she smiled back.

"Well, I'm happy for you. But if she breaks your heart I'm breaking her neck."

"Thanks."

"Don't mention it."

"So, what's it like?" Alison asked, shrugging nonchalantly as she waved a hand in the air, giving a small smile of her own. "I mean, being with a girl? Is it different than guys?"

"Well, yeah, I guess," Cosima shrugged. "I mean, girls are…I dunno. Better."

"So you're…gay-gay?"

"Gay as they come," Cosima nodded, crossing her legs beneath her to make more space for Alison to join them on Sarah's bed, and huddled up closer to the wall. "Guys are just…I dunno. Ew."

"How do you have sex with a girl?" Alison asked, eyes wide and staring at Cosima, and it was all she could do not to laugh in her sister's face as she shook her head, lower lip quivering with suppressed giggles.

"Figure it out yourself, Ali."

"Tell me!"

"Alison, do you really want to know?"

"Yes!"

"I don't think you do, Ali."

"Sarah, don't butt in!"

"Alright," Cosima surrendered, leaning in closer to Alison's ear and whispering a few words, to which Alison responded with a large, O shaped mouth and wider eyes than before. A few moments of silence followed before she looked at Cosima and pointed at her as a question formed on her lips.

"Have you…done it?"

"Yeah…" she whispered, rubbing the back of her reddening neck with a fidgeting hand as she looked down at the bed sheets. "We kind of used study group as an excuse…"

"Oh my god!"

-0-

**Age 18, Part One**

"Cosima, what on earth?!"

"Mom, I can explain."

"Oh, you better be able to, young lady."

Cosima removed the hand from her nose and dug it into her pocket, letting the light glint off of her new piercing, shuffling her feet awkwardly.

"I'm sorry?"

"For what?"

"For not asking your permission to get a nose piercing?"

"Did your sisters know about this?"

"That's just it, Mom! They dared me to do it!"

Her mother looked at her, eyes narrowing down to slits as she turned to Alison and Sarah standing behind her, both trying to hide laughter. Alison sobered up immediately, pointing at Sarah and shaking her head.

"It was her idea."

"Way to take one for the team, Ali!"

-0-

**Age 18, Part Two**

"Cosima, are you sure about this?"

"Alison, I'm sure about this," Cosima grinned as she finished rolling the joint for her sister and put it into her waiting hand, flicking a match into life. "Just remember to hold it in before you exhale."

"Will we get in trouble for this?"

"Relax, I've been smoking weed under this roof for a year now and Mom's never caught me."

"Well…alright," Alison shrugged, putting the joint between her lips and letting her sister light it for her, puffing at when she was ready. Cosima dragged from her own joint, and grinned lazily at her sister.

"Look at you, Perfect Miss Ballerina being rebellious."

"I just don't want to be left out, you know?" Alison mumbled to the bed sheets, and Cosima cocked her head to the side.

"What do you mean?"

"You and Sarah are always having so much fun. Without me."

Cosima scoffed, putting a hand under Alison's chin and making her look at her, staring her right in the eyes as she spoke.

"Listen to me, you're our sister. We love you. We'd never leave you out of anything. OK?"

"OK."

"OK. Pinky promise? Will that help?"

"Yeah."

"OK, now get high. You're gonna love it."

-0-

**Age 18, Part Three**

"Sarah, are you sure about this?"

"What, staying home after we graduate and not going to college? Yeah. I'm sure."

"Are you _sure_ sure?"

"Yes, Alison, I'm sure. God dammit."

"I just…" Alison sighed, giving a small shrug and looking at the TV, at the show neither of them was really paying attention to. "I just don't want you to be left behind."

"I want to be left behind. It'll be good for the three of us to be separated from each other. At least for now. Grow a bit on our own, you know?"

"Yeah, I get it," Alison agreed reluctantly, looking over at Sarah briefly. "You know, if you had listened to Cosima and let Rachel tutor you like she tutored Cosima…"

"Please, we both know the two of them were doing more _private_ tutoring than either of them was willing to admit."

"Well, maybe you'd have gotten better grades and gotten into a good college…"

"Alison, I don't want to go to college."

"OK. Sorry."

"It's fine. Just. Let it go OK?"

"OK."

"OK."

"Sorry."

-0-

**Age 18, Part Four**

They had decided to spend Cosima's last night in town before flying out to college in San Francisco together, and had dinner with their mother before driving out in their shared car to sit in the empty supermarket parking lot, cuddling together in the backseat as they stared up at the blank ceiling, holding hands in the steadily growing darkness.

"Guys?"

"Yeah, Ali?"

"Promise me that we'll always be close."

"Of course."

"Of course, Alison."

"Pinky promise?"

"Don't you think we're a bit too old for that nowadays?" Sarah muttered, and Cosima shoved her in the ribs, earning a small 'ow' from her.

"We're never too old for pinky promises," Cosima countered, and extender her pinky. Alison and Sarah linked theirs to hers, and the three of them unlinked and kissed the skin on their finger before going back to their previous positions, staring up at the ceiling.

"We'll always be sisters, yeah?"

"Of course."

"D'uh."

"Good."

-0-

They kept their promises, of course. They always did. They were sisters even when Cosima came home with dreadlocks, a tattoo, and a tan, and Alison and Sarah teased her about the fact that her new long term girlfriend was the one who convinced her it was a good idea to do her hair that way.

They were sisters when Alison came yelling through the living room about Donnie proposing to her the night before, and they were going to be together forever and happy at that.

They were sisters when Sarah sat in her room crying her eyes out while their mother refused to talk to her from the sheer shock that her daughter was pregnant, and didn't know who the father was.

They were sisters when Cosima broke up with her girlfriend over the phone and drank herself into a fitful sleep with a whole bottle of vodka.

They were sisters when Alison was fretting about her small, yet 'must be absolutely perfect' wedding.

They were sisters when Sarah decided to keep Kira and raise her on her own if she had to.

And throughout it all, there was always that one pinky promise in their shared car at the age of nineteen.


End file.
